cpufreq/amd-pstate-ut: Fix an "Uninitialized variables" issue

Using uninitialized value "mode2" when calling "amd_pstate_get_mode_string".
Set "mode2" to "AMD_PSTATE_DISABLE" by default.
Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
Link: https://lore.kernel.org/r/20240910233923.46470-1-qianqiang.liu@163.comAcked-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

drivers/cpufreq/amd-pstate-ut.c

@@ -267,7 +267,7 @@ static int amd_pstate_set_mode(enum amd_pstate_mode mode)
 
 static void amd_pstate_ut_check_driver(u32 index)
 {
-	enum amd_pstate_mode mode1, mode2;
+	enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;
 	int ret;
 
 	for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) {